The present invention relates to a liquid crystal device which forms text images and so on by using liquid crystal to modulate light and to an electronic apparatus which is formed using the liquid crystal device.
Recently, liquid crystal devices have been widely used in display units of electronic apparatuses such as portable computers, mobile telephones, video cameras, and so on. In general, these liquid crystal devices are formed such that a pair of substrates, each having electrodes formed thereon are bonded by a ring of sealing material such that the electrodes are oriented parallel to each other, and the liquid crystal is encapsulated in the region enclosed by the pair of substrates and the sealing material. In these liquid crystal devices, images such as text, numerals, graphics, and so on are displayed by controlling the orientation of the liquid crystal encapsulated between the pair of substrates at each pixel.
Among these liquid crystal devices, there are simple matrix liquid crystal devices which do not use active elements and active matrix liquid crystal devices which use active elements. TFD (Thin Film Diode) elements, which are two-terminal active devices, and TFT (Thin Film Transistor) elements, which are three-terminal active devices, are known as such active elements.
Conventionally, as shown in FIG. 15, for example, simple matrix liquid crystal devices which are formed such that a pair of substrates 151a and 151b made of glass or the like are bonded by a ring of sealing material 152 made of an epoxy resin or the like are known. The first one of the substrates, substrate 151a, has a substrate projecting part 153a which projects further outside than the other substrate 151b, and the other substrate 151b has a substrate projecting part 153b which projects further outside than the first substrate 151a. 
A plurality of strip-shaped electrodes 154a are formed of, for example, ITO (Indium Tin Oxide) on the inside surface of the first substrate 151a, and a plurality of strip-shaped electrodes 154b are formed of, for example, ITO on the inside surface of the other substrate 151b. When the pair of substrates 151a and 151b are bonded, these electrodes 154a and 154b orthogonally intersect each other, and each intersection point forms one pixel.
The electrodes 154a formed on the first substrate 151a have wiring lines 156a which extend onto the substrate projecting part 153a by passing through the sealing material 152, and, at the same time, also have dummy patterns 157a which pass through the sealing material 152 at the side opposite to the substrate projecting part 153a. Electrodes 154b are also formed on the other substrate 151b in the same way. Liquid crystal driving ICs (Integrated Circuits; not shown in the drawing) are mounted on the substrate projecting parts 153a and 153b, and the wiring lines 156a of the electrodes 154a and the wiring lines 156b of the electrodes 154b are connected to the terminals of these liquid crystal driving ICs.
Liquid crystal is encapsulated in the region enclosed by the substrate 151a, the substrate 151b, and the sealing material 152. This region is called a liquid crystal encapsulating region R. By controlling the voltage applied to this liquid crystal at each pixel, defined by the intersection points of the electrodes 154a and the electrodes 154b, light which is incident from outside the substrate 151a or the substrate 151b and transmitted therethrough is modulated at each pixel, and, accordingly, an image such as text is displayed on the outer side of the substrate 151a or the substrate 151b. 
In the conventional liquid crystal device, if a structure in which the wiring lines 156a pass underneath the sealing material 152 at the substrate projecting part 153a side while, on the other hand, the electrodes 154a do not pass underneath the sealing material 152 at the side opposite the substrate projecting part 153a is used, since the cell thickness at the end of the liquid crystal panel at the side opposite the substrate projecting part 153a becomes smaller by an amount equal to the part having no electrodes 154a, the cell thickness between the substrate projecting part 153a side and the side opposite thereto becomes nonuniform. When such a nonuniformity in the cell thickness occurs, the threshold voltage Vth at which the liquid crystal is turned ON/OFF becomes nonuniform between the substrate projecting part 153a side and the side opposite thereto, and, for that reason, a problem occurs in that the display quality of the liquid crystal device is reduced.
In the conventional liquid crystal device, the reason why the dummy patterns 157a, which pass underneath the sealing material 152 at part of the electrodes 154 positioned at the side opposite to the substrate projecting part 153a, are formed is that they prevent the height of the liquid crystal encapsulating region R, that is to say, the cell gap height, or in other words, the cell thickness, between the substrate projecting part 153a side and the side opposite thereto from becoming nonuniform.
However, in the conventional liquid crystal device in which the dummy patterns 157a are provided as described above, the configuration is such that the dummy patterns 157a are formed by extending the electrodes 154a while maintaining their width, and that is why the width of the dummy patterns 157a is the same as the width of the electrodes 154a. Accordingly, the ratio of the area underneath the sealing material 152 occupied by the wiring lines 156a, which pass through the sealing material 152 at the substrate projecting part 153a side, is different from the ratio of the area underneath the sealing material 152 occupied by the dummy patterns 157a, which pass through the sealing material 152 at the side opposite the substrate projecting part 153a. In particular, the ratio of the area occupied by the dummy patterns 157a at the side opposite the substrate projecting part 153a is larger.
Generally, in order to maintain the cell thickness at the sealing material, spherical or cylindrical spacers 158 are dispersed therein. However, when the ratio of the area occupied by the wiring lines 156a and the ratio of the area occupied by the dummy patterns 157a differ from each other, the number of spacers 158 sitting on top of the wiring lines 156a is not the same as the number of spacers 158 sitting on top of the dummy patterns 157a. In particular, the number at the substrate projecting part 153a side, where the area occupation ratio is small, is smaller than the number at the dummy pattern 157a side, where the area occupation ratio is large.
There is a tendency for the spacers 158 in the sealing material 152 to be compressed and crushed by the pair of substrates 151a and 151b; however, compared to the large number of spacers sitting on the dummy pattern 157a, where the area occupation ratio is large, the small number of spacers 158 sitting on the wiring lines 156a, where the area occupation ratio is small, are crushed to a greater extent. Accordingly, when the extent to which the spacers 158 are crushed at the two sides of the liquid crystal panel is different, a nonuniformity in the cell thickness occurs between one side of the liquid crystal panel and the other side, even when the dummy patterns 157a are formed. As a result, there is a problem in that the display quality deteriorates due to nonuniformity in the threshold voltage Vth.
Among liquid crystal devices, those having a structure in which liquid crystal driving ICs are directly mounted on the substrate projecting parts by the so-called COG (Chip On Glass) method are known. In these COG-method liquid crystal devices, since the plurality of electrodes which form the liquid crystal display region must be made to converge towards the terminals of the liquid crystal driving ICs on the substrate projecting parts, the wiring lines 156a of the electrodes 154a shown in FIG. 15 must be formed more finely, that is to say, with a narrower pattern width.
As a result, when the pattern width at one side becomes narrower, the extent to which the above-described spacers 158 are crushed becomes even more pronounced. Moreover, since the electrical resistance correspondingly increases when the pattern width becomes narrower, in order to prevent this, it is necessary to reduce the electrical resistance by increasing the pattern height, that is to say, by increasing the film thickness of the electrode. Increasing the film thickness of the electrode in this way causes the cell thickness nonuniformity due to the different level of crushing of the spacers 158 in the sealing material to become more pronounced.
In addition, in recent years there has been an increasing demand for liquid crystal devices capable of high-definition display and color display. In order to achieve these types of displays, the electrodes 154a and 154b shown in FIG. 15 must be made even more finely and the number of these electrodes must be increased. Such a decrease in the electrode width means that the film thickness must be increased, as described above, and as a result, the difference in the level of crushing of the spacers 158 in the sealing material induces a large cell thickness nonuniformity.
Moreover, a conventional liquid crystal device which uses a simple-matrix-type liquid crystal panel 110 shown in FIG. 16 is known. In this liquid crystal panel 110, a first substrate 111a and a second substrate 111b, which are made from glass, plastic, or the like, are bonded by a sealing material 113. Here, the structure is such that spherical or cylindrical spacers which have a diameter on the order of 5 to 10 xcexcm and which are made from, for example, resin are mixed in the sealing material 113 and the spacing between the substrates is controlled by the spacers when the first substrate 111a and the second substrate 111b are joined together during substrate bonding, thus allowing the spacing between the substrates to be precisely set to a fixed value.
In the liquid crystal panel 110, a plurality of strip-shaped first electrodes 112a are arranged in parallel to each other to extend in a predetermined direction on the surface of the first substrate 111a, that is to say, in the form of stripes. Also, on the surface of the second substrate 111b, a plurality strip-shaped second electrodes 112b are arranged in parallel to each other to extend in the direction orthogonal to the first electrodes 112a, that is to say, in the form of stripes. Then, a driving region Z is formed by horizontally and vertically arraying the regions where the first electrodes 112a and the second electrodes 112b, which are formed on the surfaces of the substrates 111a and 111b, respectively, intersect each other, that is to say, pixel regions, in the shape of a matrix.
The first substrate 111a has a substrate projecting part 114a which projects further towards the outside than the second substrate 111b. Also, the second substrate 111b has a substrate projecting part 114b which projects further towards the outside than the first substrate 1111a. First wiring lines 116a which are electrically connected to the first electrodes 112a pass through the region where the sealing material 113 is formed and are led out onto the substrate projecting part 114a. Also, second wiring lines 116b which are electrically connected to the second electrodes 112b pass through the region where the sealing material 113 is formed and are led out onto the substrate projecting part 114b. 
Input terminals 117a and 117b are formed at the outer edges of the substrate projecting parts 114a and 114b, respectively. In addition, IC chips 118a and 118b, which are formed of semiconductor ICs, are mounted at the ends of the first wiring lines 116a and second wiring lines 116b and at the ends of the input terminals 117a and 117b. 
At the opposite side from the first wiring lines 116a, the first electrodes 112a have extended dummy patterns 119a which extend outside the driving region Z. Also, at the opposite side from the second wiring lines 116b, the second electrodes 112b have extended dummy patterns 119b which extend outside the driving region Z. The extended dummy patterns 119a are connected to the first electrodes 112a, and the extended dummy patterns 119b are connected to the second electrodes 112b. 
The extended dummy patterns 119a are formed such that they pass through a part 113a of the sealing material 113, and the extended dummy patterns 119b are formed such that they pass through a part 113b of the sealing material 113. The reason for forming such a structure is as follows. The first wiring lines 116a pass through a part 113c provided towards the substrate projecting part 114a side of the sealing material 113. In addition, the second wiring lines 116b pass through a part 113d provided towards the substrate projecting part 114b side of the sealing material 113. In this state, if the extended dummy patterns 119a do not pass through the part 113a provided at the side of the sealing material 113 opposite to the substrate projecting part 114a, and furthermore if the extended dummy patterns 119b do not pass through the part 113b provided at the side of the sealing material 113 opposite to the substrate projecting part 114b, the spacing between the substrates at the positions of the parts 113c and 113d will be larger than that at the parts 113a and 113b by an amount equal to the thickness of the first wiring lines 116a and second wiring lines 116b, respectively. The reason why the extended dummy patterns 119a and extended dummy patterns 119b are formed such that they pass through the part 113a and the part 113b of the sealing material 113, respectively, is to prevent such a nonuniformity in the substrate spacing.
Therefore, by providing a structure such that the extended dummy patterns 119a and 119b pass through the parts 113a and 113b, respectively, of the sealing material 113 in the manner described above, the nonuniformity in the substrate spacing in the driving region due to each of the parts 113a, 113b, 113c, and 113d of the sealing material 113 can be reduced. Such a nonuniformity in the substrate spacing causes display nonuniformity due to differences in the liquid crystal threshold voltage. The deterioration in display quality is particularly pronounced in STN (Super Twisted Nematic) type liquid crystal display devices which are sensitive to changes in the substrate spacing.
However, for the reasons given below, it is difficult to reduce the difference between the substrate spacing at the parts 113d and 113c of the sealing material 113 and the substrate spacing at the parts 113b and 113a of the sealing material 113 to a degree which makes it possible to provide sufficiently high image quality in the liquid crystal device.
For example, as shown in FIG. 17, in order to form a row of terminals for the IC chip 118b (see FIG. 16), the width of the second wiring lines 116b is set to be narrower than the width of the second electrodes 112b. In addition, the array spacing of the second wiring lines 116b, that is to say, the spacing at which they are formed, or in other words, the pitch, is also set to be narrower than the array spacing of the second electrodes 112b. Accordingly, the extended dummy patterns 119b are formed with a width and an array spacing which are substantially the same as the second electrodes 112b. Because of this, the area occupation ratio of the second wiring lines 116b with respect to the part 113d of the sealing material 113 (in other words, the ratio of area occupied by the portions of the second wiring lines 116b which pass through the sealing material with respect to the area of the part 113d) is smaller than the area occupation ratio of the extended dummy patterns 119b with respect to the part 113b of the sealing material 113 (in other words, the ratio of area occupied by the portion of the extended dummy patterns 119b which pass through the sealing material with respect to the area of the part 113b).
For that reason, the number of spacers sitting on the second wiring lines 116b at the part 113d is less than the number of spacers sitting on the extended dummy patterns 119b at the part 113b, and, as a result, the bonding pressure applied during substrate bonding is borne by the part 113d. When this happens, a difference in substrate spacing between the part 113d and at the part 113b remains due to the difference in the degree of crushing of the spacers. The situation is exactly the same for the first electrodes 112a in FIG. 16.
Recently, there have been many demands for liquid crystal devices having high-definition display and color display capabilities. In realizing these types of display, it is necessary to increase the number of first electrodes 112a and second electrodes 112b by making their width smaller, and in this case the width of the electrodes becomes smaller. Since the electrical resistance increases as a result of reducing the electrode width in this way, it is necessary to form the first electrodes 112a and the second electrodes 112b with a larger thickness in order to prevent such an increase in electrical resistance. in this case, the first wiring lines 116a and the extended dummy patterns 119a, which are formed at the same time as the first electrodes 112a, as well as the second wiring lines 116b and the extended dummy patterns 119b, which are formed at the same time as the second electrodes 112b, also become thicker. Therefore, since the difference in the controlled force applied to the spacers with respect to the substrate spacing both in the case where the spacers sit on the wiring lines and the dummy patterns and in the case where they do not, increases, the difference in the amount of crushing of the spacers becomes larger, and, as a result, the nonuniformity in substrate spacing also becomes larger.
Furthermore, in liquid crystal devices having high-definition display and color display capabilities, the number of connection terminals of the IC chips increases corresponding to increases in the number of pixels and the number of electrodes, and, likewise, there is also a tendency for the spacing between terminals, that is to say, the terminal pitch, to be reduced. Therefore, the ratio of the width and array spacing, that is to say, the pitch, between the first electrodes 112a and the first wiring lines 116a in the driving region Z, as well as the ratio of the width and the pitch between the second electrodes 112b and the second wiring lines 116b also have a tendency to increase. As a result, the nonuniformity in substrate spacing also increases.
In Japanese Utility Model Application Publication No. 4-087822, there is disclosed a technology wherein, in a liquid crystal display panel which has a pair of glass substrates bonded by a sealing material, when the electrode width is changed at the location of the sealing portion, indentations and projections are prevented from occurring on the substrate surface corresponding to the sealing portion by forming dummy electrode patterns at the sealing portion. However, the dummy electrode patterns disclosed in that document are provided at the location of the sealing portion, and, as a result, it is difficult to make the cell gap uniform over a wide area of the liquid crystal panel.
In Japanese Patent Application Publication No. 5-203966, there is disclosed a technology wherein, in a color liquid crystal electrooptical device which is formed by bonding a color filter substrate and a transparent substrate via a sealing portion, by providing separate transparent electrode patterns as driving electrode patterns at the sealing portion, the cell gap is made more uniform than in the case in which portions where there are transparent electrodes and portions where there are no transparent electrodes both exist at the position where the sealing portion is provided. However, with the technology disclosed in that document, the electrode patterns for ensuring uniformity of the cell gap are provided linearly along the sealing material rather than being provided connected to the driving electrode patterns which pass through the sealing portion. As a result, it is difficult to make the cell gap uniform over a wide area of the liquid crystal panel.
The present invention is made in consideration of the problems mentioned above and its objective is to reduce the nonuniformity in substrate spacing, in other words, to reduce the cell thickness nonuniformity of a liquid crystal panel, by means of patterns of electrodes which are formed on the surfaces of the substrates which make up the liquid crystal device, thereby improving the liquid crystal display quality. In particular, the objective of the present invention is to make the cell thickness uniform over a wide region of the liquid crystal panel.
(1) In order to accomplish the above objective, a liquid crystal device according to the present invention comprises a pair of substrates which are bonded by a sealing material and a driving region which is formed inside the sealing material, and comprises a liquid crystal layer which is disposed between the pair of substrates and is surrounded by the sealing material; spacers which are dispersed in the sealing material; and electrodes, provided on the liquid crystal layer side of one of the substrates, including portions forming the driving region, wiring lines which overlap the sealing material at one side of the driving region while supplying a potential to the portions forming the driving region, and dummy patterns which overlap the sealing material at the other side of the driving region while being connected to the portions forming the driving region, wherein the width of the dummy patterns at a region overlapping the sealing material is smaller than the width of the portions forming the driving region.
In the liquid crystal device having this structure, since the wiring lines cross over one side of the sealing material and the dummy patterns cross over the other side of the sealing material, compared to the case in which the wiring lines cross over only one side of the sealing material, the substrate spacing, that is to say, the cell gap, can be kept uniform. Furthermore, since the width of the dummy patterns is made smaller than the width of the electrodes forming the driving region, the cell gap at the wiring line side and the cell gap at the dummy pattern side can be kept precisely uniform, even when the width of the wiring lines which extend outside the sealing material are formed smaller than the width of the electrodes forming the driving region.
(2) In the liquid crystal device according to the present invention, the width of the wiring lines at a region overlapping the sealing material may be smaller than the width of the portions forming the driving region.
In the liquid crystal device having the structure described in (1) above, the dummy patterns are made smaller than the width of the electrodes forming the driving region. Accordingly, in the liquid crystal device having the structure described in (2) above, the widths of both the wiring lines and the dummy patterns are made smaller than the width of the electrodes forming the driving region.
If the width of the wiring lines is made small, the wiring lines can be squeezed into a small area, even when the overall width of the driving region is large. Additionally, with the reduced width of the wiring lines, since the width of the dummy patterns can also be reduced, the cell gap at the wiring line side and the cell gap at the dummy pattern side can be kept precisely uniform.
(3) In the liquid crystal device according to the present invention, second dummy patterns may be provided on the liquid crystal layer side of the other one of the substrates so as to overlap the dummy patterns. Accordingly, if a pair of dummy patterns is provided so as to oppose each other on both substrates, the cell gap can be controlled and maintained even more precisely compared to the case where the dummy patterns are provided at only one side.
(4) In liquid crystal device according to the present invention, the width and spacing of the dummy patterns may be substantially the same as the width and spacing of the wiring lines. Accordingly, the liquid crystal panel cell gap from the dummy patterns to the wiring lines can be kept uniform even more precisely.
(5) In liquid crystal device according to the present invention, the width and the spacing of the dummy patterns may be made substantially the same as the width and spacing of the wiring lines by adjusting the width of the dummy patterns by forming a step in the sides of the dummy patterns. By adjusting the width of the dummy patterns by forming a step in this way, the adjustment can be carried out precisely.
(6) Next, a liquid crystal device according to the present invention comprises a pair of substrates which are bonded by a sealing material and a driving region which is formed inside the sealing material, and comprises a liquid crystal layer which is disposed between the pair of substrates and is surrounded by the sealing material; spacers which are dispersed in the sealing material; and electrodes, provided on the liquid crystal layer side of one of the substrates, including portions forming the driving region, wiring lines which overlap the sealing material at one side of the driving region while supplying a potential to the portions forming the driving region, and dummy patterns which are disposed at the other side of the driving region while being connected to the portions forming the driving region; wherein the dummy patterns have a plurality of split parts which are formed by splitting the tip of the electrodes; the plurality of split parts overlap the sealing material; and the width of each split part is smaller than the width of the respective portion forming the driving region.
According to the liquid crystal device with this structure, since the dummy patterns are formed by splitting the ends of the electrodes, the spacing between adjacent dummy patterns can be set smaller or larger to the desired spacing. Therefore, the cell gap can be controlled and maintained even more precisely.
(7) In the liquid crystal device with the structure described above, the width of the wiring lines at the region overlapping the sealing material may be smaller than the width of the portions forming the driving region.
(8) In the liquid crystal device with the structure described above, the width and spacing of the dummy patterns may be made substantially the same as the width and spacing of the wiring lines by matching the ends of the split parts and the unsplit electrodes.
(9) Next, the liquid crystal device according to the present invention comprises a pair of substrates which are bonded by a sealing material and a driving region which is formed inside the sealing material, and comprises a liquid crystal layer which is disposed between the pair of substrates and is surrounded by the sealing materials; spacers which are dispersed in the sealing material; a plurality of electrodes, provided on the liquid crystal layer side of one of the substrates, including portions forming the driving region, wiring lines which overlap the sealing material at one side of the driving region while supplying a potential to the portions forming the driving region, and dummy patterns which are disposed at the other side of the driving region while being connected to the driving region; and an IC chip which is mounted on one of the substrates and which is connected to the wiring lines; wherein each of the wiring lines is disposed so as to converge towards the IC chip from the driving region; each of the dummy patterns comprises a plurality of split parts formed by splitting the ends of the electrodes; the plurality of split parts overlap the sealing material; and the widths and spacings of the split parts and the wiring lines are substantially the same.
(10) Next, the liquid crystal device according to the present invention comprises a pair of substrates which are bonded by a sealing material and a driving region which is formed inside the sealing material, and comprises a liquid crystal layer which is disposed between the pair of substrates and is surrounded by the sealing material; spacers which are dispersed in the sealing material; a plurality of electrodes, provided on the liquid crystal layer side of one of the substrates, including portions forming the driving region, wiring lines which overlap the sealing material at one side of the driving region while supplying a potential to the portions forming the driving region, and dummy patterns which are disposed at the other side of the driving region while being connected to the portions forming the driving region; and an IC chip which is mounted on one of the substrates and which is connected to the wiring lines; wherein the individual wiring lines are disposed so as to converge towards the IC chip from the driving region; the plurality of dummy patterns include at least one of the first parts and at least one of the second parts due to the fact that the individual dummy patterns have one of a plurality of first parts which are formed by splitting the ends of the electrodes and a second part which is formed by the end of the electrodes which are not split; the first parts and the second parts overlap the sealing material; and the combined width and spacing of the first parts and the second parts are substantially the same as the width and the spacing of the wiring lines.
(11) In the liquid crystal device with the structure described above, the widths of each of the individual first parts, the individual second parts, and the individual wiring lines may be smaller than the widths of the individual portions forming the driving region.
(12) Next, the liquid crystal device according to the present invention comprises a pair of substrates which are bonded by a sealing material and a plurality of electrodes formed on a surface of at least one of the substrates, at least one of the substrates comprising a substrate projecting part which projects outside the other substrate; wherein the plurality of electrodes includes wiring lines which pass through the sealing material and extend to the substrate projecting part, and dummy patterns which pass through the sealing material at the side opposite the substrate projecting part; and the dummy patterns are formed with a width which is smaller than the width of the electrodes which are in a portion surrounded by the sealing material.
In such a liquid crystal device, since it is possible to reduce the dimensional differences in the width of the dummy patterns and the width of the wiring lines by forming the dummy patterns to be narrower than the electrodes, the nonuniformity in the liquid crystal panel cell gap between the wiring line side and the dummy pattern side can be reduced, and, as a result, the display quality of the liquid crystal device can be improved.
(13) In the liquid crystal device with the structure described above, the area occupation ratio of portions of the dummy patterns which pass through the sealing material is substantially the same as the area occupation ratio of portions of the wiring lines which pass through the sealing material.
In the liquid crystal device having such a structure, since the status of the area with respect to the sealing material at the dummy pattern side and the status of the area with respect to the sealing material at the wiring line side are substantially the same, the cell gap nonuniformity of the liquid crystal panel can be reduced still further.
Moreover, the terms xe2x80x9carea occupation ratioxe2x80x9d referred to in the structure described above mean the proportion of the area of the dummy patterns passing underneath the sealing material based on the area of the electrodes passing underneath the sealing material in the case where the electrodes pass through the sealing material with their original width unchanged, the proportion of the area of the wiring lines passing underneath the sealing material based on the area of the electrodes passing underneath the sealing material in the case where the electrodes pass through the sealing material with their original width unchanged, and so on. Furthermore, the meaning of the term xe2x80x9csubstantially the samexe2x80x9d of course includes cases which are exactly the same, but also includes cases which, although not exactly the same, differ to such an extent that there are no negative effects in terms of function.
(14) In the liquid crystal device with the structure described above, the area occupation ratio of the portions of the dummy patterns which pass through the sealing material and the area occupation ratio of the portions of the wiring lines which pass through the sealing material may each be approximately 40% or more. Accordingly, the nonuniformity in the cell thickness of the liquid crystal panel can be suppressed while, at the same time, allowing the resistance of the electrodes, or in other words, the thickness of the electrodes, to be set to an appropriate value.
(15) In the liquid crystal device with the structure described above, gap-forming material, or spacers may be included in the sealing material. According to the present invention, since the dummy patterns are formed with a width which is smaller than the width of the electrodes in the portion surrounded by the sealing material, the dimensional difference between the width of the dummy patterns and the width of the wiring lines is reduced, and therefore, the difference between the number of spacers sitting on the wiring lines and the number of spacers sitting on the dummy patterns is reduced. As a result, since there is substantially no difference in the degree of crushing of the spacers at the wiring line side and the degree of crushing of the spacers at the dummy pattern side, the nonuniformity in cell thickness of the liquid crystal panel can be reduced, and accordingly, the display quality of the liquid crystal device can be improved.
(16) In the liquid crystal device with the structure described above, an IC chip may be directly mounted on the surface of the substrate projecting part and the wiring lines may be connected to terminals of the IC chip. With this structure, the present invention is applied to a so-called COG-type liquid crystal device. In the COG-type liquid crystal device, since the plurality of electrodes inside the liquid crystal display region must be made to converge towards the terminal part of the IC chip on the substrate projecting part, the width of the individual wiring lines which pass through the sealing material must be made small. According to the present invention, if the width of the dummy patterns at the side opposite to the wiring lines is formed to be smaller than the width of the electrodes in the portion surrounded by the sealing material, it is possible to bring the width of the dummy patterns close to the width of the wiring lines at the side opposite thereto. Therefore, for a COG-type liquid crystal panel, the cell thickness can be kept uniform over a wide area.
(17) In the liquid crystal device with the structure described above, color filters may be formed on one of the surfaces of the pair of substrates, and the electrodes may be formed on one of the pair of substrates in correspondence with the individual color elements of the color filters. This structure is an application of the present invention to a liquid crystal device capable of color display.
Since the color filters are generally formed by R (red), G (green), and B (blue) individual color elements, the number of electrodes must be three times larger than in the case of a black and white monochrome display, and therefore, the width of the electrodes must be made even smaller. Reducing the thickness of the electrodes means that the electrical resistance of the electrodes increases by that amount, and in order to avoid this, the film thickness of the electrodes must be increased. Accordingly, when the film thickness of the electrodes is large, if the number of spacers sitting on the wiring lines at one end of the electrodes is different from the number of spacers sitting on the dummy patterns at the other end of the electrodes, and it means that, as a result of the difference, nonuniformity in the cell thickness easily occurs between the wiring line side and the dummy pattern side.
In the above phenomenon, as in the present invention, if the width of the dummy patterns at the side opposite the wiring lines is formed smaller than the width of the electrodes in the portion surrounded by the sealing material, since it is possible to bring the width of the dummy patterns close to the width of the wiring lines at the side opposite thereto, the number of spacers sitting on the dummy patterns can be brought close to the number of gap members sitting on the wiring lines at the side opposite thereto. Therefore, it is possible to reliably prevent the cell thickness from becoming nonuniform even in a liquid crystal panel capable of color display in which the electrode film thickness tends to be increased.
(18) In the liquid crystal device with the structure described above, stripe-shaped electrodes which orthogonally intersect each other may be formed on the pair of substrates, and the liquid crystal device may be a simple matrix type in which each of the orthogonally intersecting portions forms a pixel.
Among liquid crystal devices, there are active-matrix-type liquid crystal devices which use active elements and simple-matrix-type liquid crystal devices which do not use active elements. In the simple-matrix-type liquid crystal devices, generally, stripe-shaped electrodes which orthogonally intersect each other are formed on a pair of substrates, each intersecting portion forms one single pixel, and a plurality of the pixels are arranged in the form of a dot matrix overall. The present invention is preferably applied to such a simple-matrix-type liquid crystal device. The reason is that, in the simple-matrix-type liquid crystal device, a difference in the width of the patterns between the wiring lines at the substrate projecting side and the dummy patterns at the side opposite thereto easily occurs.
(19) Next, the electronic apparatus according to the present invention comprises a liquid crystal device and a control circuit for controlling the operation of the liquid crystal device; wherein the liquid crystal device comprises a pair of substrates bonded by a sealing material and a plurality of electrodes formed on the surface of at least one of the substrates, at least one of the substrates comprising a substrate projecting part which projects outside the other substrate; the plurality of electrodes comprises wiring lines which pass through the sealing material and extend to the substrate projecting part and dummy patterns which pass through the sealing material at the side opposite to the substrate projecting part; and the dummy patterns are formed with a width which is smaller than the width of the electrodes in a portion surrounded by the sealing material.
(20) Next, the liquid crystal device according to the present invention comprises a pair of substrates bonded by a sealing material and a plurality of electrodes formed on the surface of at least one of the substrates, a driving region being provided inside the sealing material; wherein the electrodes comprise wiring lines which pass through a part of the sealing material which is formed at one side of the driving region and are led to the outside, and dummy patterns which are on the surface of at least one of the pair of substrates and which pass through a part of the sealing material which is formed at the other side of the driving region; and the dummy patterns are formed so as to pass through the sealing material with a width and a spacing which are different from the width and the spacing of the electrodes inside the driving region.
According to this invention, by forming the dummy patterns so that they pass through the sealing material with a width and a spacing which are different from the width and the spacing of the electrodes inside the driving region, even if there is a large difference between the width and spacing of the electrodes and the width and spacing of the wiring lines, since it is possible to bring them close to the width and the spacing of the portions of the wiring lines passing through the sealing material, the difference between the area occupation ratio of the dummy patterns and the area occupation ratio of the wiring lines with respect to the sealing material is reduced, and it is possible to achieve a substrate spacing which does not widely vary along the sealing material while, at the same time, allowing the difference in substrate spacing at the portions of the sealing material at either side of the driving region to be reduced. Accordingly, the substrate spacing in the driving region can be kept uniform and the display quality can be improved.
(21) In the liquid crystal device with the structure described above, the dummy patterns may be connected to the electrodes. The dummy patterns in this structure are electrically connected to the wiring lines which form the electrodes or part of the electrodes, and are formed on the surface of one of the substrates as part of the electrodes.
(22) In the liquid crystal device with the structure described above, the dummy patterns may be at least one part of dummy patterns formed on the surface of the other substrate opposite to the electrodes.
In this structure, the dummy patterns may be electrically connected to the electrodes or the wiring lines, or alternatively, they may be independent dummy patterns which are not electrically connected to electrodes and the wiring lines. Independent dummy patterns are normally formed so as to oppose the dummy patterns which are connected to the electrodes.
In the present invention, as described above, the dummy patterns are formed for reducing the difference of the sizes of spaces formed between the substrates via sealing material. The wiring lines pass one of the spaces, and no wiring line passes the other of the spaces, and furthermore, they are provided so that the portion outside the driving region and inside the region where the liquid crystal is encapsulated by the sealing material does not appear to be very different from the driving region.
As described above, the dummy patterns may be formed on either one of the pair of substrates, or alternatively, they may be formed on both of the substrates so that the dummy patterns are oriented parallel to each other. Accordingly, even if the dummy patterns which pass through the sealing material are formed on either one of the pair of substrates, there is no change in their effect on the substrate spacing. Furthermore, when there are dummy patterns opposing the wiring lines, it is preferable for the dummy patterns to be formed so as to be oriented parallel to each other on both substrates.
(23) In the liquid crystal device with the structure described above, the dummy patterns may be formed so as to pass through the sealing material with a width and a spacing which lean more towards the width and the spacing of the wiring lines than the width and the spacing of the electrodes inside the driving region.
For example, when the width and spacing of the wiring lines are smaller than the width and spacing of the electrodes, the dummy patterns are formed so as to pass through the sealing material with a width and a spacing which are smaller than the width and the spacing of the electrodes.
According to the liquid crystal device having this structure, the difference between the substrate spacing affected by the dummy patterns passing through the sealing material and the substrate spacing affected by the wiring lines can be reduced compared to the case in which the dummy patterns are formed with the same width and spacing as the electrodes.
(24) In the liquid crystal device with the structure described above, the dummy patterns may be formed so as to pass through the sealing material with a width and a spacing which are closer to the width and the spacing of the wiring lines than the width and the spacing of the electrodes inside the driving region. More preferably, the dummy patterns are formed so as to pass through the sealing material with a width and a spacing which are substantially the same as the width and the spacing of the wiring lines.
(25) In the liquid crystal device with the structure described above, the area occupation ratio of the dummy patterns with respect to the sealing material may be formed so as to lean more towards the value of the area occupation ratio of the wiring lines with respect to the sealing material than the area occupation ratio in the case where the electrodes inside the driving region pass through the sealing material unchanged.
For example, in the case where the area occupation ratio of the wiring lines is smaller than the area occupation ratio of the electrodes when it is assumed that the electrodes are formed so as to extended and pass through the sealing material with their original, unchanged width and spacing, the dummy patterns are formed so as to pass through the sealing material with an area occupation ratio which is smaller than the area occupation ratio of the electrodes assumed above.
Accordingly, since it is possible to reduce the difference between the area occupation ratio of the dummy patterns and the area occupation ratio of the wiring lines, the difference in substrate spacing between the part in the sealing material at one side of the driving region and the part at the other side can be reduced.
(26) In the liquid crystal device with the structure described above, the area occupation ratio of the dummy patterns with respect to the sealing material may be formed so as to be closer in value to the area occupation ratio of the wiring lines with respect to the sealing material than the area occupation ratio in the case where the electrodes inside the driving region pass through the sealing material unchanged. More preferably, the area occupation ratio of the dummy patterns with respect to the sealing material is set to be substantially the same as the area occupation ratio of the wiring lines with respect to the sealing material.
In the structure described above, the term xe2x80x9carea occupation ratioxe2x80x9d means the proportion of the area of the parts of the wiring lines or dummy patterns which pass through the sealing material with respect to the area of the sealing material, and this area occupation ratio is set according to the width and spacing of the wiring lines or dummy patterns. More concretely, in the case where a plurality of patterns are arrayed along the sealing material, the proportion of area mentioned above means the ratio of the passing area of the pattern with respect to the total area of the sealing material in one period within those array periods. Therefore, if the array period is constant, the area occupation ratio is also constant along the sealing material; however, if the array period is not constant, the area occupation ratio varies along the sealing material.
(27) Next, a liquid crystal device according to the present invention comprises a pair of substrates bonded by a sealing material, a plurality of first electrodes formed on the surface of one of the substrates, and a plurality of second electrodes formed on the surface of the other substrate, a driving region being provided inside the sealing material; wherein the first electrodes are provided with wiring lines which pass through a part of the sealing material formed at one side of the driving region and which are led towards the outside; the second electrodes are provided with dummy patterns which pass through a part of the sealing material formed at the other side of the driving region; and the dummy patterns are formed with a width which is different from the width of the first electrodes.
According to this liquid crystal device, by forming the dummy patterns with a width which differs from the width of the first electrodes, when the width of the first electrodes and the width of the wiring lines are different, by making the width of the dummy patterns different from the width of the first electrodes, it is possible to reduce the difference between the substrate spacing at a part of the sealing material at one side of the driving region and the substrate spacing at a part of the sealing material at the other side of the driving region.
(28) In the liquid crystal device according to the present invention, the dummy patterns may be formed so as to pass through the sealing material with a width and a spacing which leans more towards the width and the spacing of the wiring lines than the width and the spacing of the first electrodes inside the driving region. For example, in the case where the width and spacing of the wiring lines are smaller than the width and spacing of the electrodes, the dummy patterns are formed so as to pass through the sealing material with a width and a spacing which are smaller than the width and the spacing of the electrodes.
(29) In the liquid crystal device with the structure described above, the dummy patterns may be formed so as to pass through the sealing material with a width and a spacing which is closer to the width and the spacing of the wiring lines than the width and the spacing of the first electrodes inside the driving region. More preferably, the dummy patterns are formed so as to pass through the sealing material with a width and a spacing which are substantially the same as the width and the spacing of the wiring lines.
(30) In the liquid crystal device with the structure described above, the area occupation ratio of the dummy patterns with respect to the sealing material may be formed so as to lean more towards the value of the area occupation ratio of the wiring lines with respect to the sealing material than the area occupation ratio when it is assumed that the electrodes inside the driving region are extended and pass through the sealing material with the original width and spacing thereof unchanged.
For example, in the case where the area occupation ratio of the wiring lines is smaller than the area occupation ratio of the electrodes when it is assumed that the electrodes formed so as to extend and pass through the sealing material with their original, unchanged width and spacing, the dummy patterns are formed so as to have an area occupation ratio which is smaller than the area occupation ratio of the electrodes assumed above.
(31) In the liquid crystal device with the structure described above, the area occupation ratio of the dummy patterns with respect to the sealing material may be formed so as to be closer in value to the area occupation ratio of the wiring lines with respect to the sealing material than the area occupation ratio when it is assumed that the electrodes inside the driving region are extended and pass through the sealing material with the original width and spacing thereof unchanged. More preferably, the area occupation ratio of the dummy patterns with respect to the sealing material is formed to be substantially the same as the area occupation ratio of the wiring lines with respect to the sealing material.
(32) Next, a liquid crystal device according to the present invention comprises a pair of substrates bonded by a sealing material, a plurality of first electrodes formed on the surface of one of the substrates, and a plurality of second electrodes formed on the surface of the other substrate, a driving region being provided inside the sealing material; wherein the first electrodes are provided with wiring lines which pass through a part of the sealing material formed at one side of the driving region and which are led towards the outside, and first dummy patterns which pass through a part of the sealing material formed at the other side of the driving region; the second electrodes are provided with third dummy patterns which oppose the wiring lines, and second dummy patterns which oppose the first dummy patterns; and the sum of the area occupation ratio of the first dummy patterns with respect to the sealing material and the area occupation ratio of the second dummy patterns with respect to the sealing material has a value which leans more towards the sum of the area occupation ratio of the wiring lines with respect to the sealing material and the area occupation ratio of the third dummy patterns with respect to the sealing material than two times the area occupation ratio when it is assumed that the first electrodes are extended and pass through the sealing material with the original width and spacing thereof unchanged.
For example, in the above assumption, in the case where the sum of the area occupation ratio of the wiring lines and the area occupation ratio of the third dummy patterns is smaller than two times the area occupation ratio of the first electrodes, the sum of the area occupation ratio of the first dummy patterns with respect to the sealing material and the area occupation ratio of the second dummy patterns with respect to the sealing material is formed so as to be smaller than two times the area occupation ratio of the first electrodes in the above assumption.
Since the liquid crystal device having the structure described above is formed such that the first electrodes and the second electrodes are each formed on the surfaces of the pair of substrates, the wiring lines and the third dummy patterns oppose each other and pass through a part in the sealing material at one side of the driving region, and the first dummy patterns and the second dummy patterns oppose each other and pass through a part in the sealing material at the other side of the driving region, the substrate spacing at the part of the sealing material at one side of the driving region is set according to the passing aspect of the wiring lines and the third dummy patterns, while the substrate spacing at the part of the sealing material at the other side of the driving region is set according to the passing aspect of the first dummy patterns and the second dummy patterns.
As described above, since the sum of the area occupation ratio of the first dummy patterns and the area occupation ratio of the second dummy patterns has a value which leans more towards the sum of the area occupation ratio of the wiring lines and the area occupation ratio of the third dummy patterns than two times the are occupation ratio of the first electrodes, compared with the case, which the dummy patterns are formed by extending the first electrodes without changing their width and the spaces between the first electrodes, and the second dummy patterns are formed in the same width and the spaces of the first electrodes, as well as the above assumption, the difference of the sizes of the spaces between the substrates is reduced.
(33) In the liquid crystal device with the structure described above, the sum of the area occupation ratio of the first dummy patterns with respect to the sealing material and the area occupation ratio of the second dummy patterns with respect to the sealing material may be closer in value to the sum of the area occupation ratio of the wiring lines with respect to the sealing material and the area occupation ratio of the third dummy patterns with respect to the sealing material than two times the area occupation ratio when it is assumed that the first electrodes are extended and pass through the sealing material with the original width and spacing thereof unchanged.
More preferably, the sum of the area occupation ratio of the first dummy patterns with respect to the sealing material and the area occupation ratio of the second dummy patterns with respect to the sealing material is set to be substantially the same as the sum of the area occupation ratio of the wiring lines with respect to the sealing material and the area occupation ratio of the third dummy patterns with respect to the sealing material.
(34) Next, a liquid crystal device according to the present invention comprises a pair of substrates bonded by a sealing material, a plurality of first electrodes formed on the surface of one of the substrates, and a plurality of second electrodes formed on the surface of the other substrate, a driving region being provided inside the sealing material; wherein the first electrodes are provided with wiring lines which pass through a part of the sealing material formed at one side of the driving region and which are led towards the outside, and first dummy patterns which pass through a part of the sealing material formed at the other side of the driving region; the second electrodes are provided with third dummy patterns which oppose the wiring lines, and second dummy patterns which oppose the first dummy patterns; the sum of the width of the parts of the first dummy patterns which pass through the sealing material and the width of the parts of the second dummy patterns which pass through the sealing material has a value which leans more towards the sum of the width of the parts of the wiring lines which pass through the sealing material and the width of the parts of the third dummy patterns which pass through the sealing material than two times the width of the first electrodes; and the sum of the spacing between the parts of the first dummy patterns which pass through the sealing material and the spacing between the parts of the second dummy patterns which pass through the sealing material has a value which leans more towards the sum of the spacing between the parts of the wiring lines which pass through the sealing material and the spacing between the parts of the third dummy pattern which pass through the sealing material than two times the spacing between the first electrodes.
For example, when the sum of the width of the wiring lines and the width of the third dummy patterns is smaller than two times the width of the first electrodes, the sum of the width of the part passing the sealing material at the first dummy patterns and the width of the part passing the sealing material at the second dummy patterns is formed to be smaller than two times the width of the first electrodes, and furthermore, when the sum of the spacing between the wiring lines and the spacing between the third dummy patterns is smaller than two times the spacing between the first electrodes, the sum of the spacing between portions passing the sealing material at the first dummy patterns and the spacing between portions passing the sealing material at the second dummy patterns is formed to be smaller than two times the spacing between the first electrodes.
According to the liquid crystal device having the structure described above, regarding the wiring lines and the third dummy patterns which pass both the front and rear surfaces of the part at one side of the sealing material, as well as the first dummy patterns and second dummy patterns which pass both the front and rear surfaces of the part at the other side of the sealing material, because both the sum of the widths and the sum of the spacings are closer in value to each other than two times the width and two times the spacing of the first electrodes, the difference in substrate spacing at both portions of the sealing material can be reduced.
(35) In the liquid crystal device with the structure described above, the sum of the width of the parts of the first dummy patterns which pass through the sealing material and the width of the parts of the second dummy patterns which pass through the sealing material may be closer in value to the sum of the width of the parts of the wiring lines which pass through the sealing material and the width of the parts of the third dummy patterns which pass through the sealing material than two times the width of the first electrodes; and the sum of the spacing between the parts of the first dummy patterns which pass through the sealing material and the spacing between the parts of the second dummy patterns which pass through the sealing material may be closer in value to the sum of the spacing between the parts of the wiring lines which pass through the sealing material and the spacing between the parts of the third dummy pattern which pass through the sealing material than two times the spacing between the first electrodes.
More preferably, the sum of the width of the part passing the sealing material at the first dummy patterns and the width of the part passing the sealing material at the second dummy patterns is set to be substantially the same as the sum of the width of the part passing the sealing material at the wiring lines and the width of the part passing the sealing material at the third dummy patterns, and furthermore, the sum of the spacing between the parts passing the sealing material at the first dummy patterns and the spacing between the parts passing the sealing material at the second dummy patterns is set to be substantially the same as the sum of the spacing between the parts passing the sealing material at the wiring lines and the spacing between the parts passing the sealing material at the third dummy patterns.
(36) In the liquid crystal device with the structure described above, spacers for regulating the spacing between the substrates may be mixed in the sealing material. Since the degree of crushing of the spacers changes according to increases and decreases in the area occupation ratios of the individual patterns passing through the sealing material and the substrate spacing changes in response to this degree of crushing, the present invention is particularly effective when applied to the case where the spacers are mixed in the sealing material.
(37) The liquid crystal device with the structure described above may form a simple-matrix-type liquid crystal panel by forming electrodes, which orthogonally intersect each other, in the form of stripes on each of the surfaces of the pair of substrates. The present invention can be applied to such a simple-matrix-type liquid crystal panel and also to an active-matrix-type liquid crystal panel; however, it is preferably applied to the simple-matrix-type liquid crystal panel. The reason is that, in the simple-matrix-type liquid crystal panel, a difference in pattern width between the wiring lines and the electrodes easily occurs.
(38) The liquid crystal device with the structure described above further comprises color filters including a plurality of color elements, wherein, the plurality of electrodes which are formed on the surface of one of the pair of the substrates are formed at each color element.
In the case where color filters are used, as in this liquid crystal device, since it is necessary to provide the electrodes corresponding to each of the plurality of color elements (for example, the three colors, red, green, and blue), the number of electrodes increases and, as a result, it is necessary to reduce the electrode width. In this case, in order to control the increase in electrical resistance, the electrodes must be formed with a thickness which is increased by that amount, and therefore, the effect on the substrate spacing due to the difference in area occupation ratios of the individual patterns passing through the sealing material is large. Furthermore, since an increase in the number of electrodes increases the overall degree of convergence of the wiring lines, the difference between the width of the electrodes and the width of the wiring lines as well as the difference between the spacing between the electrodes and the spacing between the wiring lines increase. Therefore, a difference in substrate spacing easily occurs, and for that reason, it is particularly effective to apply the present invention.
(39) In the liquid crystal device with the structure described above, an IC chip may be mounted on at least one of the pair of substrates and the wiring lines may be connected to terminals of the IC chip.
In the liquid crystal device having the structure described above, since it is necessary to converge the wiring lines towards the terminal portion of the mounted IC chip, the difference between the wiring line width and the electrode width as well as the difference between the wiring line pitch and the electrode pitch are easily increased, and therefore, it is particularly effective to apply the present invention.
(40) Next, the electronic apparatus according to the present invention comprises a liquid crystal device and control means for controlling the operation of the liquid crystal device, wherein the liquid crystal device may be formed of the liquid crystal device having the various structures described above. As such an electronic apparatus, as long as it is provided with a liquid crystal device, the kind of apparatus is not significant; however, in particular, portable electronic devices such as mobile telephones, mobile information terminals, etc. are suitable.